How does the B-21 Compare to the Stealth Bomber?

Editor’s Note: Northrop-Grumman’s original Stealth Bomber and the Air Force’s Long Range Strike-Bomber bare such a striking resemblance, to one another, it’s reasonable to wonder what else the two aircraft have in common. There’s a lot of speculation as to whom the subcontractors are or will be, how the design compares in its LO characteristics to its predecessor, and many other questions that, realistically, will go unanswered for classification and security concerns. Even so, imaginations are running wild as to what will make this beast so special.

First and foremost, the new B-21 looks very similar to its B-2 Spirit predecessor. In fact, the new aircraft look startlingly similar to the original Advanced Strategic Penetration Aircraft (ASPA) and the later Advanced Technology Bomber concept from the 1980s that ultimately resulted in the B-2. But the Spirit was redesigned late in the game to operate at low altitudes after Dr. Paul Kaminski’s—current chairman of the Defense Science Board—Red Team cautioned that the B-2 might have to resort to low-level penetration as the Soviets built new, more capable radars—as legendary Aviation Week journalist Bill Sweetman points out in his book “Inside the Stealth Bomber.” The redesign caused a decrease in range and payload, as well as a larger radar cross-section.

The B-2 Spirit is a multi-role bomber capable of delivering both conventional and nuclear munitions. A dramatic leap forward in technology, the bomber represents a major milestone in the U.S. bomber modernization program. The B-2 brings massive firepower to bear, in a short time, anywhere on the globe through previously impenetrable defenses. (U.S. Air Force photo)

If the current B-21 design is truly representative of the direction the Air Force is taking, the new aircraft will take the B-2’s all-aspect stealth design to the next level. Particularly, the B-21’s low observable design will be more effective against low frequency radars operating in the UHF and VHF bands, which are increasingly coming into vogue as a means to counter stealth aircraft. Indeed, as then Air Force chief of staff Gen. Norton Schwartz told the House Armed Services Committee in 2012, even the B-2 is starting to lose its ability penetrate hostile airspace. “The technology on which they were designed with respect to signature management . . . is ‘80s vintage,” Schwartz told the committee, adding, “the reality is that the B-2 over time is going to become less survivable in contested airspace.”

The B-21 design—which is similar to the original high-attitude optimized B-2 design—is built to counter the low frequency radars that can detect and track tactical fighter-sized stealth aircraft. Unlike an F-22 or F-35, which are designed to operate in an environment where the enemy might be aware of their presence, the B-2 and B-21 are designed to avoid detection altogether.